"The Countdown Reflection" season finale episode of "The Big Bang Theory," airing May 10, 2012

CBS

(CBS News) Thursday sees the season finale of two popular shows: CBS' "The Big Bang Theory" and The CW's "The Vampire Diaries."

A lot of decisions will be made on the season three finale episode of "The Vampire Diaries," titled "Departed."

Stefan and Damon leave Mystic Falls on a mission, but soon split up when Elena needs one of them. Caroline and Tyler are forced to make a life-changing decision, while Jeremy also makes a decision that will change everything.

The episode description leaves a lot up to the imagination, but Nina Dobrev, who portrays Elena Gilbert on the show, dished to E! News about what viewers can expect.

"The stakes are really high in this one," she said. "Somebody has to die, if not more than one person has to die for the others to survive, so there's suspense and everyone's on their toes. At the same time, with the family, seeing all the flashbacks and how everything went down is very emotional and sad. Once someone dies, it's sad, too. It's a crazy one."

Meanwhile, wedding bells could be ringing on the season five finale of "The Big Bang Theory."

When Howard and Bernadette decide they want to be married before his NASA launch, the gang rushes to put on a wedding.

But questions remain: Will they actually exchange vows? And will Howard go off to space?

"The Big Bang Theory" star Jim Parsons told "CBS This Morning," "There are great expectations for matrimony. There are great expectations for space travel. And I don't know if I'm allowed to tell you if either of those have lift-off, but you might see it."

And if this provides any clues, Melissa Rauch, who portrays Bernadette, told TVGuide.com she cried while shooting the last scene of the show, adding, "I felt very bad for the makeup people because every take, she had to fix my eye makeup. It got really bad!"